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oai:www.ideals.illinois.edu:2142/29410 2023-07-10 col_2142_8888 col_2142_5131 com_2142_8887 com_2142_234 com_2142_5130

Eden, James G. Eden, James G. Cunningham, Brian T. Schutt-Ainé, José E. Park, Sung-Jin Zheng, Jie 2012-02-01T00:44:51Z 2014-02-01T11:00:24Z 2012-02-01T00:44:51Z 2011-12 A detailed investigation of the design, fabrication, and characterization of a novel optically tunable external cavity ring laser is described here. The external cavity laser (ECL) utilizes a semiconductor optical amplifier as the gain medium in a ring configuration, and a surface photonic crystal incorporating a superstrate layer of an azobenzene solution as the wavelength-selective element. Wavelength tuning is realized through optical illumination of a thin layer of azobenzene, which causes a refractive index change of the azobenzene molecules produced by photon-induced, cis→trans isomerization, thus leading to controlled tuning of the external cavity laser emission. The ECL system is stable, compact, and exhibits single-mode emission at the Bragg wavelength of the surface photonic crystal. The lasing threshold of the ECL with respectto current is ~186 mA, and the emission spectrum has a line-width as narrow as 0.05 nm, which is limited by the resolution of the spectrometer. Under a driving current of 200 mA, an output power of 500 mW is obtained, with a side-mode-suppression ratio (SMSR) of 21.8 dB. While exposed to optical illumination from a continuous Nd:YVO4 laser, the ECL demonstrates single-mode emission over a tuning wavelength range of 842 to 848 nm. The emission peak shift occurs on a timescale of minutes, and is completely reversible upon termination of the pump Nd:YVO4 laser. This optically tunable external cavity ring laser represents a departure from conventional tunable ECLs insofar as the elimination of mechanically movable parts is concerned. The result is an easy and accurate approach to remotely wavelength tuning the laser. The wavelength-selective element of the surface photonic crystal is fabricated on a plastic substrate using a replica-molding technique, which allows for inexpensive submicron structure production over large surface areas. Due to the control it provides over laser emission wavelength, as well as its reduced weight and complexity, compactness, and attractiveness for mass production, this optically tunable external cavity ring laser is expected to find applications in optically integrated systems and future photonic circuits. Item withdrawn by Mark Zulauf (zulauf@illinois.edu) on 2011-08-09T14:50:54Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 2 Zheng_Jie.doc: 4960256 bytes, checksum: 6b81a462218f7298d58dbbad547be8ae (MD5) Zheng_Jie.pdf: 3150396 bytes, checksum: 48904395f5de695481d870cfc7a6c30b (MD5) Made available in DSpace on 2012-02-01T00:44:51Z (GMT). No. of bitstreams: 3 Zheng_Jie.pdf: 3150433 bytes, checksum: 38c8a6bb58e624aaf5a92b26644e1834 (MD5) license.txt: 4058 bytes, checksum: 6703d760ba7dc8c4bfd0910d88b157b5 (MD5) Zheng_Jie.doc: 4960256 bytes, checksum: 6b81a462218f7298d58dbbad547be8ae (MD5) Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by William Ingram (wingram2@illinois.edu) on 2012-02-01T00:50:14Z Item is restricted until 2014-02-01T00:50:07Z Item reinstated by Sarah Shreeves (sshreeve@illinois.edu) on 2014-02-01T11:00:23Z Item was in collections: Dissertations and Theses - Electrical and Computer Engineering (ID: 446) Graduate Theses and Dissertations at Illinois (ID: 204) No. of bitstreams: 4 Zheng_Jie.pdf: 3150433 bytes, checksum: 38c8a6bb58e624aaf5a92b26644e1834 (MD5) license.txt: 4058 bytes, checksum: 6703d760ba7dc8c4bfd0910d88b157b5 (MD5) Zheng_Jie.doc: 4960256 bytes, checksum: 6b81a462218f7298d58dbbad547be8ae (MD5) Zheng_Jie.pdf.txt: 204019 bytes, checksum: 2c0484d31ea8a422da3bb298202958ba (MD5) Item released from any restrictions by Sarah Shreeves (sshreeve@illinois.edu) on 2014-02-01T11:00:24Z http://hdl.handle.net/2142/29410 en Copyright 2011 Jie Zheng Laser External cavity Optically tunable. Optically tunable external cavity ring laser Electrical & Computer Eng 1933 Electrical & Computer Engr 1200 University of Illinois at Urbana-Champaign Dissertation Ph.D. PHD:Electr & Computer Eng-UIUC 10KS1200PHD